Fuse plug



Feb. 15, 1938. T DALCHER 2,108,106

FUSE' PLUG Filed April 5, 195? r InvenZxor:

J 2 I John l'flalche Patented Feb. 15, 1938 UNITED STATES PATENT OFFICE 12 Claims.

This invention relates to fuse plugs and has for its object the production of a plug which may be readily made in mass production by fully automatic machines.

5 Another object of the invention is the production of such a fuse plug in which all contacts are made by pressure and in which no soldering or cementing is used, in this manner effectually preventing the corroding of any of the elements 10 thereof.

A further object of the invention is in widely separating the contacts so that the forming of an arc is prevented. 1

A further object of the invention is to give 15 clear visibility through the body portion thereof making the fuse plugs safer in case of a blowout.

These objects are attained by the mechanism illustrated in the accompanying drawing.

20 For the purpose of illustrating the invention, one preferred form thereof is illustrated in the drawing, this form having been found to give satisfactory and reliable results, although it is to be understood that the various instrumentali- 25 ties of which the invention consists can be variously arranged and organized, and the invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described except as required by 30 the scope of. the appended claims.

Of the drawing:

Figure 1 represents a vertical section of a fuse plug embodying the principles of the present invention and drawn to an enlarged scale.

35 Figure 2 represents an inverted plan of the same, a portion of the screw shell being broken away.

Figure 3 represents a plan of the ribbon holder.

40 Figure 4 represents a plan of the contact holder.

Figure 5 represents a plan of the fuse ribbon, and

Figure 6 represents an elevation of portions of the body and contact holder slightly separated and showing the coacting serrations on the opposed faces thereof.

Figures 2 to 6 inclusive are drawn to an en- 50 larged scale but at a scale reduced from that of Fig. 1.

Similar characters indicate like parts throughout the several figures of the drawing.

In the drawing, I is the body portion of the 55 fuse plug preferably made of glass giving clear visibility therethrough to ascertain if the fuse is in working condition.

I is a narrow ribbon preferably of zinc, which ribbon is placed against'the under side of the body portion I0 and then is forced into a chamher |2 in the body portion I0 by means of the insertion into said chamber of the ribbon holder l3.

This ribbon holder 3 is reversible, both ends being alike and the central part II thereof is 10 provided with a plurality of serrations I5 on opposite faces thereof.

The ribbon H is of sufficient length to extend over the top and periphery of the ribbon holder |3 with ends I6, I! extending downwardly therefrom.

One end l6 of the ribbon H is forced against the serrations l5 by means of a contact holder l8 forced into the under recess IQ of the ribbon holder l3.

This contact holder I8 is reversible, both ends being alike and has mounted in its center a contact 20 preferably formed of aluminum and having at opposite ends enlarged heads 20.2: which will prevent any end movement of said contact 20 in the bore of its holder I8.

The ribbon holder l3 and contact holder l8 are preferably made of bakelite or hard rubber.

The contact holder I8 is provided with an an nular flange 2| having radial depressions or serrations 22 formed in the opposite faces thereof.

The other end ll of the ribbon passes over the fiange 2| and rests against the under side of said flange over the radial serrations 22 therein.

The lower end of the body portion I0 has formed on its outer surface a helical thread |0x with which coacts a screw shell23 preferably made of vbrass.

When this screw shell 23 is threaded to the body portion l0 it will be rotated sufficiently 40 to force upwardly the ribbon holder |3 with the end l6 of the ribbon firmly pressed against the serrations I 5 which will impinge thereon and hold it in position.

When the screw shell 23 is mounted on the member |0 an inwardly extending flange 24 thereon is beneath the under face of the flange 2| and at this time the extreme end of the portion ll of the ribbon II is interposed between the flanges 2| and 24 and it is locked in position by forming indentations 25 in this inwardly extending flange 24, said indentations entering the lower serrations 22.

The indentations are not formed until the upper serrations 22 of flange 2| have entered the serrations 26 in the lower end of body portion 8 U and are engaged thereby.

A portion of the end I! of the ribbon H will be forced in this manner into engagement with the lower serrations 22 formed in the flange 2| rations 22 will eifectually prevent any rotation of screw shell 23 relatively to the body portion iii.

The contact member 20 has formed on itsouter end characters 21 to indicate the amperage of any particular fuse plug. v

The fuse ribbon II is provided with the usual narrowed portion 28, as indicated in Fig. 5.

In assembling the various elements the plunger of a machine forming the characters 21 is retained against the contact 20 while the screw shell is being threaded to body Hi.

This screw shell 22 is rotated until the horizontal portion 29 of ribbon H is jammed tight between the serrations 26 in the under side of body i and the upper serrations 22 in the flange 2i.

If the screw shell 23 is prevented from rotating by the means herein described, it is obvious that all separation of the various elements of the plug is effectually prevented.

All of the elements of the fuse plug are therefore locked together preventing any movement of one element relatively to the other elements and the fuse plug is ready for use.

The machine for producing these fuses on a quantity production basis takes care of all the operations described above, in addition it cuts the fuse ribbon, being fed from a reel and also punches the gap of ribbon. It also tests each plug before it leaves the machine and bad plugs are automatically rejected.

The radial serrations 26 in the lower end of the body portion l8 and the radial serrations 2'3 on each side of the flange 25 of contact hoider it, are made symmetrical and are adapted to accurately interlock so that duringthe assembling of the fuse plug the body portion if) and the contact holder l8 are effectually prevented from an rotation relatively to each other. 4

By this means any twist or torsional deflection of the ribbon will be effectually eliminated while the screw shell 23 is being screwed into position.

In the assembling machine the top of the fuse plug is always so located that the ribbon H will be positioned between two flat surfaces, one on the machine and the other on the upper end of the fuse plug, as for instance, the flat face 28, the ribbon being centrally disposed relatively to these fiat surfaces.

It is believed that the operation and many advantages of the invention will be understood without further description.

Having thus described my invention, I claim:

1. A fuse plug comprising a body portion, a fuse ribbon; a ribbon holder in the lower end of said body; a contact holder in the lower end of said ribbon holder and engaging the fuse ribbon;

and means preventing the separation of sale;

parts and the rotation thereof relative to each other. I

2. A fuse plug comprising a body portion, a fuse ribbon; a ribbon holder in the lower end of said body; a contact holder in the lower end of said ribbon holder; and a metal shell preventing the separation of said parts and the rotation thereof relative to each other, one end of said ribbon contacting with said shell and the other end contacting with said contact member.

3. A fuse plug comprising a body portion, a fuse ribbon; a ribbon holder in the lower end of said body; a contact holder in the lower end of said ribbon holder; a contact in said contact holder engaging the fuse ribbon and having enlarged portions at opposite ends contacting with the opposite ends of the contact holder; and means preventing the separation of said parts and the rotation thereof relative to each other.

4. A fuse plug comprising a body portion, a fuse ribbon; a ribbon holder in the lower end of said body; a contact holder in the lower end of said ribbon holder; a contact member immovably mounted in the holder therefor and projecting beyond the opposite end thereof; and a metal shell threaded to said body portion and including means for preventing the separation of said parts and the rotation thereof relative to each other, one end of said ribbon contacting with said shell and the other end contacting with said contact member.

5. A fuse plug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in its lower end; a contact holder the upper end of which is insertable into said recess with the contact thereof contacting with one end of said ribbon; a metal screw shell threaded to said body portion and contacting with the other end of said ribbon; and means preventing the separation of said parts.

6. A fuse plug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a reversible ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in each end; a contact holder the upper end of which is insertable into the lower recess with the contact thereof contacting with one end of said ribbon; a metal screwvshell threaded to said body portion and contacting with the other end of said ribbon; and means preventing the separation of said parts.

7. A fuse plug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in its lower end; a reversible contact holder the upper end of which is insertable into said recess with the contact thereof contacting with one end of said ribbon; a metal screw shell threaded to said body portion and contacting with the other end of said ribbon; and means preventing the separation of said parts.

8. A fuse plug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in its lower end, the inner end wall of said recess being provided with a plurality of serrations; a contact holder the upper end of which is insertable into said recess with the contact thereof contacting with one end of said ribbon and retaining it against said serrations; a metal screw shell threaded to said body portion and contacting with the other end of said ribbon; and means preventing the separation of said parts.

9. A fuse plug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in its lower end; a contact holder the upper end of which is insertable into said recess with the contact thereof contacting with one end of said ribbon, said contact holder having an annular flange; means for locking said flange to body portion; a metal screw shell threaded to said body portion and contacting with the other end oi said ribbon; and means preventing the separation of said parts.

10, A fuse plug comprising a transparent body portion having a chamber inits lower end; a fuse ribbon; a ribbon holder insertable into said cham-= ber to position said ribbon, said holder having a recess in its lower end; a contact holder the upper end of which is insertable into said recess with the contact thereof contacting with one end of said ribbon, said contact holder having an annular flange with a plurality of radial depressions therein; and a metal screw shell threaded to said body portion and contacting with the other end of said ribbon, said shell having an inwardly extending flange with a plurality of projections in said flange depressions.

11. A fuseplug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in its lower end, the-inner end wall of said recess being provided with a plurality of serrations; a contact holder the upper end of which is insertable into said recess; a contact immovably mounted in the contact holder and adapted to force one end of said ribbon against said serrations; a metal screw shell threaded to said body portion and contacting with the other end of said ribbon; and means preventing the separation of said parts.

12. A fuse plug comprising a transparent body portion having a chamber in its lower end; a fuse ribbon; a ribbon holder insertable into said chamber to position said ribbon, said holder having a recess in its lower end; a contact holder the upper end of which is insertable into said recess; a contact centrally disposed in said holder and contacting with one end of said ribbon, said contact holder having an annular flange provided JOHN T. DALCHER. 

